Answer:
5 gallons per fish
Explanation:
Your first answer is correct because anytime a line passes through the origin, it is proportional.
To find the number of gallons per fish, we can take the first point which is (2, 10) and divide it by 2; (2÷2, 10÷2) = (1, 5)
This means that for every fish you get, you will need 5 gallons of water to meet the requirement.
Best of Luck!